1. Field of the Invention
The present invention relates to an image capture apparatus having an image stabilization function.
2. Description of the Related Art
There is known an image capture apparatus having a shake correction function (optical image stabilization function) of detecting a shake of the image capture apparatus and driving a movable imaging lens to correct an image blur arising from the shake. There is also proposed an image stabilization function (electronic image stabilization function) of controlling an image readout position in moving image shooting in a direction in which the movement of an image caused by a shake is canceled. This function is used in compact, lightweight image capture apparatuses and mobile phones equipped with image capture apparatuses. Image stabilization of this type is called electronic image stabilization.
Recently, there is also known a technique of widening the image stabilization range on the wide-angle side in moving image recording to enhance the image stabilization effect, compared to the conventional one, for a large image blur generated by shooting during walking or the like. At this time, there is also known a technique of obtaining a greater correction effect by using both optical image stabilization and electronic image stabilization so as to cope with a larger image blur.
The following technique is known as the technique using optical image stabilization and electronic image stabilization. For example, in Japanese Patent Laid-Open No. 2010-004370, a detected image blur signal is divided into high and low frequencies by a filter. The high-frequency image blur is corrected by optical image stabilization, and the low-frequency image blur is corrected by electronic image stabilization. This makes control calculation efficient, enhancing the correction effect.
In Japanese Patent No. 2803072, when the image blur amount falls within a range of up to a predetermined value, an image blur is corrected by electronic image stabilization. When the image blur amount is equal to or larger than the predetermined value, an image blur is corrected by optical image stabilization. As a result, the correction range is simply widened, enhancing the correction effect.
Although image stabilization can be implemented during exposure by optical image stabilization, it cannot be performed during exposure by electronic image stabilization because image stabilization is performed by image extraction. In Japanese Patent Laid-Open No. 2010-004370, therefore, only optical image stabilization can be performed during still image exposure. In addition, in Japanese Patent Laid-Open No. 2010-004370, only a high-frequency image blur is subjected to optical image stabilization. As a result, only high-frequency image stabilization can be performed in still image shooting. Further, this technique has problems that a filter for dividing a frequency is necessary, and that the calculation load and program volume increase owing to calculation of an optical image stabilization amount and calculation of an electronic image stabilization amount after division, and the like.
In Japanese Patent No. 2803072, there is a boundary between electronic image stabilization and optical image stabilization. At this boundary, an image is disturbed under the influence of an overshoot upon driving for optical image stabilization, and the like.